Publications by authors named "Olga Isaeva"

Inflammatory cytokines are pivotal to immune responses. Upon cytokine exposure, cells enter an "alert state" that enhances their visibility to the immune system. Here, we identified an alert-state subpopulation of ribosomes defined by the presence of the P-stalk.

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  • Immune checkpoint inhibition (ICI) combined with chemotherapy is the standard treatment for stage II-III triple-negative breast cancer, but the effectiveness of ICI alone remains unclear.
  • The adaptive BELLINI trial found that short-term ICI treatments led to immune activation in a significant portion of patients, correlating immune response with tumor-infiltrating lymphocytes.
  • A new cohort is being studied with patients who have high levels of these lymphocytes; early results show a notable rate of major and complete pathological responses post-treatment, suggesting that neoadjuvant ICI could be a promising approach without chemotherapy.
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Since 2012, universal single-dose HAV vaccination in children aged 3 years and older has been implemented in the Tyva Republic, a region of the Russian Federation. The aim of this prospective non-interventional observational single-center study was to determine the immunological and epidemiological effectiveness of single-dose vaccination against hepatitis A 9 to 11 years after its implementation. The anti-HAV IgG antibodies were determined in two independent cohorts of children who were vaccinated with a single dose of monovalent pediatric inactivated vaccine (HAVRIX 720 EU) in Tyva in 2012 and recruited 9 years (Year 9 Cohort) and 11 years (Year 11 Cohort) after immunization.

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Transfusion-transmitted hepatitis E virus (HEV) infection is an increasing concern in many countries. We investigated the detection rate of HEV viremia in blood donors in Russia. A total of 20,405 regular repetitive voluntary non-renumerated blood donors from two regions (Moscow and Belgorod) were screened for HEV RNA using the cobas HEV test in mini-pools of six plasma samples.

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  • * Hepatitis A showed increasing prevalence with age, while hepatitis E and B were detected at rates of 4.1% and 4.6%, respectively, with no cases of HBV in those under 30, highlighting a successful vaccination program.
  • * The study found that while HBV strains were local and date back centuries, hepatitis C strains were introduced from other regions in the late 20th century, indicating a need for better screening and care for viral hepatitis in these populations.
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  • The study investigates the prognostic significance of BRCA1-related biomarkers in young, node-negative, chemotherapy-naïve triple-negative breast cancer (TNBC) patients, focusing on how these biomarkers influence overall survival outcomes.
  • It included 485 Dutch women diagnosed with TNBC under age 40, assessing their BRCA1 status and tumor-infiltrating lymphocytes (sTILs) to determine outcomes over a 15-year period.
  • Results showed that patients with pathogenic germline BRCA1 mutations had worse survival rates compared to those without alterations, but higher levels of sTILs significantly improved overall survival, particularly in patients with tumor BRCA1 promoter methylation.
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The clinical successes of immune checkpoint blockade (ICB) in advanced cancer patients have recently spurred the clinical implementation of ICB in the neoadjuvant and perioperative setting. However, how neoadjuvant ICB therapy affects the systemic immune landscape and metastatic spread remains to be established. Tumors promote both local and systemic expansion of regulatory T cells (T), which are key orchestrators of tumor-induced immunosuppression, contributing to immune evasion, tumor progression and metastasis.

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Invasive lobular breast cancer (ILC) is the second most common histological breast cancer subtype, but ILC-specific trials are lacking. Translational research revealed an immune-related ILC subset, and in mouse ILC models, synergy between immune checkpoint blockade and platinum was observed. In the phase II GELATO trial ( NCT03147040 ), patients with metastatic ILC were treated with weekly carboplatin (area under the curve 1.

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  • Russia initiated a neonatal vaccination against Hepatitis B (HBV) 20 years ago, followed by catch-up immunizations for those under 60 starting in 2006, and this study evaluates the immunity and infection rates across different regions.
  • Testing of 36,149 volunteers revealed a low HBsAg detection rate of 0.8%, with 2.4% in the Republic of Dagestan, while vaccinated individuals showed less than 0.3% HBsAg detection but a 7.4% rate of ongoing HBV circulation among those under 20 years.
  • Despite a stable prevalence of immune-escape HBsAg variants (around 25%), the wild-type HBV population significantly decreased in size
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The factors influencing hepatitis E virus (HEV) circulation remain largely unexplored. We investigated HEV seroprevalence in humans and the prevalence of infection in farm pigs and rabbits in different regions of the Russian Federation, as well as the genetic diversity and population dynamics of the HEV. The anti-HEV IgG antibody detection rates in the general population increase significantly with age, from 1.

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Immune checkpoint blockade (ICB) has heralded a new era in cancer therapy. Research into the mechanisms underlying response to ICB has predominantly focused on T cells; however, effective immune responses require tightly regulated crosstalk between innate and adaptive immune cells. Here, we combine unbiased analysis of blood and tumors from metastatic breast cancer patients treated with ICB with mechanistic studies in mouse models of breast cancer.

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The hepatitis delta virus (HDV) is believed to be a vanishing infection in countries with successful hepatitis B virus (HBV) vaccination programs. We assessed the current status of HDV infection in Tuva, a region of the Russia that has been highly endemic for HBV. The proportion of HDV-infected patients among HBsAg-positive patients in the regional registry in 2020 was 32.

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  • * In areas without universal mass vaccination (UMV), seroprevalence has shifted to older age groups, while regions with child vaccination programs saw significant increases in HERD immunity among younger populations.
  • * The findings indicate a need for national implementation of UMV, along with strategies to improve vaccination coverage and conduct catch-up campaigns to sustain the effectiveness of existing programs.
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Since the start of the COVID-19 pandemic, mutations have led to the emergence of new SARS-CoV-2 variants, and some of these have become prominent or dominant variants of concern. This natural course of development can have an impact on how protective the previously naturally or vaccine induced immunity is. Therefore, it is crucial to understand whether and how variant specific mutations influence host immunity.

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Background: The geographic distribution of the hepatitis B virus (HBV) and the hepatitis D virus (HDV) genotypes is uneven. We reconstructed the temporal evolution of HBV and HDV in Yakutia, one of the regions of Russia most affected by HBV and HDV, in an attempt to understand the possible mechanisms that led to unusual for Russia pattern of viral genotypes and to identify current distribution trends.

Methods: HBV and HDV genotypes were determined in sera collected in 2018-2019 in Yakutia from randomly selected 140 patients with HBV monoinfection and 59 patients with HBV/HDV.

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Background: The study aimed to investigate hepatitis C virus (HCV) specific markers in chronically infected children. The main objective was to explore the patterns of marker variability.

Methods: HCV RNA, core antigen, anti-HCV IgM, and antibodies to individual viral proteins were detected using commercially available assays or experimental ELISA.

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Background: Hepatitis E virus (HEV) is a major causative agent of acute hepatitis worldwide, prompting continuous HEV vaccine efforts. Vaccine development is hampered by the lack of convenient animal models susceptible to infection with different HEV genotypes. We produced recombinant open reading frame 2 protein (pORF2; p551) of HEV genotype (GT) 3 and assessed its immunogenicity and protectivity against HEV challenge in common marmosets (Callithrix jacchus, CM).

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Immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) have revolutionized the treatment of melanoma patients. Based on early studies addressing the mechanism of action, it was assumed that PD-1 blockade mostly influences T cell responses at the tumor site. However, recent work has demonstrated that PD-1 blockade can influence the T cell compartment in peripheral blood.

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Only a subgroup of triple-negative breast cancer (TNBC) responds to immune checkpoint inhibitors (ICI). To better understand lack of response to ICI, we analyze 681 TNBCs for spatial immune cell contextures in relation to clinical outcomes and pathways of T cell evasion. Excluded, ignored and inflamed phenotypes can be captured by a gene classifier that predicts prognosis of various cancers as well as anti-PD1 response of metastatic TNBC patients in a phase II trial.

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The clinical use of molecular targeted therapy is rapidly evolving but has primarily focused on genomic alterations. Transcriptomic analysis offers an opportunity to dissect the complexity of tumors, including the tumor microenvironment (TME), a crucial mediator of cancer progression and therapeutic outcome. TME classification by transcriptomic analysis of >10,000 cancer patients identifies four distinct TME subtypes conserved across 20 different cancers.

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The COVID-19 pandemic caused by SARS-CoV-2 is a continuous challenge worldwide, and there is an urgent need to map the landscape of immunogenic and immunodominant epitopes recognized by CD8 T cells. Here, we analyze samples from 31 patients with COVID-19 for CD8 T cell recognition of 500 peptide-HLA class I complexes, restricted by 10 common HLA alleles. We identify 18 CD8 T cell recognized SARS-CoV-2 epitopes, including an epitope with immunodominant features derived from ORF1ab and restricted by HLA-A*01:01.

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Universal hepatitis B vaccination of newborns was implemented in Russia starting from 1998. From 1998 to 2019, the incidence of acute hepatitis B reduced from 43.8 to 0.

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Since August 2012, universal single-dose vaccination in children aged at least three years has been implemented in the Republic of Tuva, which was previously the region most affected by hepatitis A in Russia. The objective of this cross-sectional study was the assessment of the immunological and epidemiological effectiveness of vaccination program five years following its implementation. In the pre-vaccination period, anti-HAV antibody detection rates in Tuva was 66.

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Motivation: Identification of differentially expressed genes is necessary for unraveling disease pathogenesis. This task is complicated by the fact that many diseases are heterogeneous at the molecular level and samples representing distinct disease subtypes may demonstrate different patterns of dysregulation. Biclustering methods are capable of identifying genes that follow a similar expression pattern only in a subset of samples and hence can consider disease heterogeneity.

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Intestinal health relies on the immunosuppressive activity of CD4 regulatory T (T) cells. Expression of the transcription factor Foxp3 defines this lineage, and can be induced extrathymically by dietary or commensal-derived antigens in a process assisted by a Foxp3 enhancer known as conserved non-coding sequence 1 (CNS1). Products of microbial fermentation including butyrate facilitate the generation of peripherally induced T (pT) cells, indicating that metabolites shape the composition of the colonic immune cell population.

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